Abstract: A method and apparatus for measuring tension imposed on a cable by a pull line in a conduit includes a tension meter coupled between the cable and the pull line. The meter includes a load cell connected to an electronic circuit to operate an audio transmitter in one embodiment, or to generate an electromagnetic field parallel to the conduit according to a second embodiment. The electromagnetic field induces a tension signal in a metallic conductor extending parallel to the conduit. In a further embodiment, electrical conductors form two of many warp threads of a pull line that also includes a weft thread. The audio or electrical signal is transmitted for detection and for operating a display. An operator uses the display to control tension in the pull line.

Abstract: Method and system for characterizing a vertical modified in situ oil shale retort prior to ignition of the retort. The retort is formed by mining a void at the bottom of a proposed retort in an oil shale deposit. The deposit is then sequentially blasted into the void to form a plurality of layers of rubble. A plurality of units each including a tracer gas cannister are installed at the upper level of each rubble layer prior to blasting to form the next layer. Each of the units includes a receiver that is responsive to a coded electromagnetic (EM) signal to release gas from the associated cannister into the rubble. Coded EM signals are transmitted to the receivers to selectively release gas from the cannisters. The released gas flows through the retort to an outlet line connected to the floor of the retort. The time of arrival of the gas at a detector unit in the outlet line relative to the time of release of gas from the cannisters is monitored.

Abstract: A portable leak detector is disclosed for use with, say, helium as a tracer gas. The leak detector includes an improved separation chamber, an air pump for pumping the sample gas, a high vacuum spectrometer, and a small and lightweight evacuation pump. The separation chamber is formed by an air-tight enclosure which has an inlet duct, an outlet duct, and a tubular separation membrane extending between manifolds connected to the ducts. Gas samples are collected by a gas sampling probe and pumped by an air pump into the inlet duct of the separation chamber, through multiple parallel tubes of the tubular membrane material, and out the outlet duct of the separation chamber where it is exhausted. The multiple tubes are formed of a selectively-permeable membrane material such as Tefzel which permits the rapid diffusion of helium therethrough but which has relatively low permeability for other gases contained in the gas sample.

Abstract: In an exemplary embodiment, a measuring cell is disposed in an outer tube. A chamber in the outer tube adjacent the measuring cell can be directly connected via an opening to the liquid in a liquid vessel whose pressure is to be measured. In order to also be able to calibrate the pressure transducer at any time in the liquid vessel, an elastic container is inventively disposed in the chamber, the container being connected to a connecting line likewise lying in the outer tube for the purpose of filling and emptying. In its filled state, the container closes the opening of the chamber without interrupting the connection between a fluid line used for calibration and the measuring cell.

Abstract: A vortex shedding device for use in measuring air flow rate into an internal combustion engine includes a duct provided therein with an element for forming vortices in air flowing through the duct. A pair of hot wires is located in the duct which are alternately exposed to vortices generated by the vortex forming element. The hot wires are associated with an electric circuit which detects variations in the resistances of the hot wires and determines the frequency at which vortices are generated in air flowing past the vortex forming element. The electric circuit contains a vortex detector for each of the hot wires so that even if one of the hot wires is broken, a pulse signal is still provided during steady operation of the engine.

Abstract: A fixed reference capacitance (10) and a variable, pressure sensitive capacitance (12) are defined by a common conductive layer (14), and a common dielectric layer (16). A peripheral conductive layer 20 completes the reference capacitor and a central conductive layer (22) completes the variable capacitor. A peripheral supporting layer or structure (18) prevents the thickness or the dielectric constant of the dielectric layer peripheral portion but not the central portion from varying in response to pressure changes. In this manner, the reference and variable capacitors may be placed closely adjacent without pressure isolating the reference capacitor. An oscillator (30) provides an AC, such as square wave, driving signal to first and second temporary storage capacitors (52, 54). A bridge (70) of CMOS transistors selectively connects the first and second storage capacitors with the reference and variable capacitors.

Abstract: The disclosure relates to an air pressure sensor comprising a first air passage, a branch passage having an opening into the air passage, a sensor in the branch passage responsive to variation in air pressure in the opening and jet means for air flow through the first passage adjacent the opening to the branch passage to create an increased depression in static pressure as compared with the remainder of the air passage to enhance the response of the pressure sensor in the branch passage when air flow through the first passage occurs. The air passage terminates in a probe having an orifice to be opened and closed by the absence of and presence of a surface in contact with the probe so that the pressure sensor indicates whether or not the probe is in contact with the surface.

Abstract: A hydrostatic pipe tester is especially designed for testing pipe at high pressures safely. Threaded tension rods are supported on both sides of the pipe under test such that their axes are coplaner with the pipe under test, and coupling assemblies couple the pipe under test to the threaded tension rods within the plane. A novel bleeding assembly and a novel check valve is also disclosed.

Abstract: A device capable of measuring the position of the level surface of a molten metal bath by exploiting a microwave signal emerging from a waveguide which impinges perpendicularly onto the molten metal so as to originate a standing wave, the position of which is determined by the position of the level surface. The parameters of the standing wave are detected so as to obtain an indication as to the level.

Abstract: An apparatus and process for detecting a single specific chemical solid or gas in the presence of other chemical solids or gases or for detecting a number of specific mixed chemical solids or gases. The apparatus and process passes multiple beams of electromagnetic radiation incident on the material in a sample chamber producing acoustic signals at specific frequencies when light of specific wavelengths is absorbed. The electromagnetic radiation is selected to have wavelengths corresponding to optical absorption features of at least one specific chemical in the sample chamber. The acoustic signals are detected by at least one beat tone or combination tone characteristic of and representative of the degree of absorption by a specific chemical or multiple specific chemicals desired to be detected. The apparatus and process are especially useful in leak detection in natural gas systems and for detection of pollutants, explosive gases and the like.

Abstract: A differential pressure measuring system is disclosed. The system includes two quartz capacitive pressure transducers (14, 16). Each capsule contains a pressure sensitive capacitor (Csa, Csb) and a relatively pressure invariable reference capacitor (Cra, Crb). The pressure sensitive capacitors (Csa, Csb) are excited by out-of-phase signals, (Vr, -Vr) which further excite the reference capacitors (Cra, Crb), out of phase, respectively. The outputs of all capacitors are combined in a summing junction (22) whose output controls the count of a digital integrator (34). A closed loop is formed by converting the output of the integrator (34) to a negative feedback signal (lf) which is applied to the summing junction (22) through a feedback capacitor (Cf). The integrator (34) incrementally changes the feedback signal (lf) in a direction to balance the loop. At this point the output of the integrator (34) is representative of the measured differential pressure.

Abstract: This invention provides a device for measuring a whole day urinary output, which includes an outer cylindrical container and an inner hollow tubular container to be positioned in the outer cylindrical container for sampling the urinary from the outer container. In one aspect, the inner container is vertically studded in the outer container and both containers are openably-closably communicated with each other at the bottom of the device and the inner container has an openably-closably communicated with the reservoir. In the other aspect, the inner hollow tubular container is a portable sampling tube used in combination with a packing plug. The packing plug has a hollow cylindrical portion and a plug body having a frustoconical head integrally formed with the hollow cylinder and a cylindrical portion underlying the head.

Abstract: An apparatus and process for locating gas leaks in underground pipelines by detection of sound waves created by the leaking gas. The apparatus and process uses a sound transducer attached to an elongated probe inserted in the ground for a substantial portion of its length. The elongated probe and transducer combination has an effective mechanical resonant frequency equal to or below the electrical resonant frequency of the sound transducer. The passive sonic detection apparatus and process of this invention provides improved sensitivity for detection of sounds created by leaking gas and thereby more accurate pinpointing of the gas leak in an underground pipeline. In one embodiment acoustic reflection and absorption shielding is provided for reduction of system response to airborne noise.

Abstract: For testing the dynamic characteristics of a motor vehicle, an endless movable road surface for supporting and moving with respect to motor vehicles. The motor vehicle is restrained from movement but its wheels are permitted to move in contact with the simulated road surface. The simulated road surface may be the periphery of a wheel whose circumference is relatively large compared to the wheel base of the automobile, or it may be a relatively flat run of an endless belt supported on multiple rollers. In either case, all the wheels of the motor vehicle are supported by the simulated road surface. Preferably the effective inertial load of the simulated road surface is adjusted to be approximately equal to the mass of the motor vehicle. One or more of a plurality of selectably attachable inertial masses may be coupled to the system to permit the inertial mass of the system to vary according to the inertial mass of the vehicle being tested.

Abstract: A magnetic cartridge such as a pick-up or cutter, whose magnetic circuits are at least partly hollow, the cavities extending mainly in the direction of the magnetic flux. Each magnetic circuit and in particular each polepiece is formed at least partly with a slot communicating with the cavity and extending substantially in the same direction. This reduces eddy-current losses in the magnetic circuit, thereby improving the treble reproduction of the pick-up.

Abstract: A load cell comprises a semiconductor diaphragm which includes an outer flange portion, a central rigid portion having a smaller thickness than the outer flange portion and a thin resilient portion provided between the outer flange portion and the central rigid portion. At least two piezo-resistors constituting at least part of a bridge circuit are formed in the resilient portion. The load cell further comprises a first glass block secured to the central rigid portion, and a second glass block for securing the outer flange portion. A load is applied to the semiconductor diaphragm through the first glass block, wherein measurement of the applied load is effected by detecting variation in resistance of the resistor bridge circuit.

Abstract: A rheometer for measuring the extrudate swell of polymeric solutions. The eometer has an upper and lower transparent reservoir with a capillary tube therebetween. The flow of solution between reservoirs from upper to lower is provided by gas pressure. Initially, the swell is photographed and the lower reservoir is then filled with an immiscible Newtonian fluid. In sequence the flow is again started and a second photograph is taken. The first and second swell are measured, and the results applied to a formula to determine the first normal stress difference of the polymeric solution.

Abstract: An output signal of a vibration sensor mounted on an internal combustion engine is compared with a background noise reference signal to produce a knock signal which can accurately represent the intensity of knocking. The background noise level signal is produced by averaging a component of the vibration sensor output signal which represents the vibration of the engine other than knock-induced vibration. In order to produce a feedback signal for inhibiting the knock induced component of the sensor output signal, a first comparator compares the sensor output signal with a first reference signal having a sufficiently low level. Knock signal is produced by a second comparator which receives a second reference signal, which is proportional to the first reference signal but having sufficiently higher level, thereby enabling a precise determination of knock intensity.

Abstract: A measurement system is provided in which a work-engaging transducer is connected by means of a cable to a remotely located display unit which is adapted to provide quasi-analog and/or digital display of measurement made by the transducer. The transducer includes an oscillator the output of which is a function of a measurement being made. The display unit presents the measurement made in quasi-analog and/or digital form either in a conventional format such as a circular dial face, in linear form such as a column 82 or in other selected formats of various geometrical configurations and/or in various mathematical progressions to suit particular applications.

Abstract: A temperature probe is formed by enclosing a thermistor in a sensor sheath one of whose ends is closed and in engagement with the thermistor, and by biasing the thermistor into engagement with the inner surface of the sheath. The biasing is accomplished by coiling the transistor wires and using them as a compression spring. A closed air space is formed within the sheath by closing its other end with the end of a coaxial cable and overmolding an outer housing.